The present disclosure relates to friction drive belts.
V-ribbed belts having a large number of pores on their surfaces, which are to contact pulleys, have been known.
For example, Japanese Patent Publication No. 2007-255635 describes a friction drive belt having a friction drive surface made of a porous rubber composition having an air content of 5-20% and containing ultra high molecular weight polyethylene as a lubricant.
Japanese Patent Publication No. 2006-064015 describes a friction drive belt having a friction drive surface made of a rubber composition into which short fibers that are not subjected to a surface treatment are blended, wherein holes due to the loss of the short fibers and/or spaces each formed between the short fiber and the rubber are formed on the surface of the friction drive belt.
Japanese Domestic Re-Publication of PCT International Application No. 2008/007647 describes a friction drive belt in which at least a part of a belt body in contact with a pulley, is made of an elastomer composition, wherein a large number of cellular pores of hollow particles are formed in a pulley contacting surface.
Japanese Domestic Re-Publication of PCT International Application No. 2009/101799 describes a friction drive belt for transmitting power which is wrapped around a pulley such that a compression rubber layer provided on an inner periphery of a belt body is in contact with the pulley, wherein the compression rubber layer in which a plurality of pores of hollow particles having an average pore size of 5-120 μm are formed has an air content of 5-40%.